Immediate hypersensitivity to iodinated contrast media: diagnostic accuracy of skin tests and intravenous provocation test with low dose.

BACKGROUND: The diagnosis of HSR to iodinated contrast media (ICM) is challenging based on clinical history and skin tests. OBJECTIVE: This study evaluates the negative predictive value (NPV) of skin tests and intravenous provocation test (IPT) with low-dose ICM in patients with suspected immediate hypersensitivity reaction (HSR) to ICM. METHODS: Thirty-seven patients with suspected immediate hypersensitivity reaction to ICM were included retrospectively. Skin tests and a single-blind placebo-controlled intravenous provocation test (IPT) with low-dose iodinated contrast media (ICM) were performed. RESULTS: Skin tests with ICM were positive in five cases (one skin prick test and five intradermal test). Thirty-six patients were challenged successfully by IPT, and only one patient had a positive challenge result, with a grade I reaction by the Ring and Messmer classification. Ten of 23 patients followed up by telephone were re-exposed to a negative tested ICM during radiologic examination; two experienced a grade I immediate reaction. CONCLUSIONS & CLINICAL RELEVANCE: For immediate hypersensitivity reaction to ICM, the NPV for skin tests and IPT with low dose was 80% (95% CI 44-97%).

[Acute blue urticaria following subcutaneous injection of patent blue dye]. / Urticaire bleue aiguë après injection sous-cutanée de bleu patenté.

BACKGROUND: Patent blue (PB) is a lymphatic vessel dye commonly used in France for sentinel lymph node detection in breast cancer, and less frequently in melanoma, and which may induce hypersensitivity reactions. We report a case of acute blue urticaria occurring within minutes of PB injection. PATIENTS AND METHODS: Ten minutes after PB injection for sentinel lymph node detection during breast cancer surgery, a 49-year-old woman developed generalised acute blue urticaria and eyelid angioedema without bronchospasm or haemodynamic disturbance, but requiring discontinuation of surgery. Skin testing using PB and the anaesthetics given were run 6 weeks after the episode and confirmed PB allergy. PB was formally contra-indicated. DISCUSSION: Immediate hypersensitivity reactions to PB have been reported for between 0.24 and 2.2% of procedures. Such reactions are on occasion severe, chiefly involving anaphylactic shock. Two mechanisms are probably associated: non-specific histamine release and/or an IgE-mediated mechanism. Skin tests are helpful in confirming the diagnosis of PB allergy. CONCLUSION: Blue acute urticaria is one of the clinical manifestations of immediate hypersensitivity reactions to patent blue dye. Skin tests must be performed 6 weeks after the reaction in order to confirm the diagnosis and formally contra-indicate this substance.

[A study of 19 cases of allergy to heparins with positive skin testing]. / Étude de 19 cas d'allergie aux héparines prouvée par des tests cutanés.

BACKGROUND: Allergic hypersensitivity to unfractioned or low-molecular-weight heparins is uncommon but is known, and in particular the most common form is localized dermatitis, although such cases have seldom turned into maculopapular exanthema. Since cross-reactions with other heparins are frequent, identification of therapeutic alternatives is essential. PATIENTS AND METHODS: This retrospective study included patients referred to the Department of Dermatology and Allergology at Tenon Hospital between 2000 and 2012 with suspicion of allergy to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) and sensitized to at least one heparin (i.e. positive skin tests to at least one heparin). The heparins and hirudins used were tested in the forearm by means of intradermal skin tests. All patients were contacted in 2012 to establish whether they had used some form of heparin since the cutaneous allergy tests. RESULTS: Nineteen patients had at least one positive skin test for heparin; 1 patient had presented anaphylactic shock, while 18 others had presented localized eczema (12) or generalized dermatitis (6). The heparin most often responsible for these adverse reactions was enoxaparin (13/19). An LMWH was responsible in most cases (18 vs. 1 with UFH). Of these 18 patients, 16 also presented positive skin tests for UFH, 9 for synthetic heparinoid and 1 for hirudin. 11/19 patients were tested for fondaparinux (a synthetic pentasaccharid) and all had negative skin tests. 5/7 patients with negative skin tests had taken fondaparinux without any visible reaction, whereas 2 who also tested negative experienced localized eruption at the injection site. DISCUSSION: Our results underline the greater frequency of delayed hypersensitivity reactions compared with immediate reactions to heparins. Skin tests can help to identify substitution molecules. Fondaparinux might be an alternative but certain diagnosis relies on rechallenge.

Outcome of patients with interstitial lung disease admitted to the intensive care unit.

INTRODUCTION: The outcome of acute respiratory failure (ARF) affecting patients with various interstitial lung diseases (ILD) is poorly defined particularly in those with drug-induced ILD (DI-ILD). We investigated this issue focusing on fibrosing idiopathic interstitial pneumonitis (FIIP) and DI-ILD. METHODS: We carried out a retrospective study of patients with ILD admitted in a single center ICU. The primary end-point was in-hospital mortality. RESULTS: We included 72 subjects who fell into 3 diagnostic groups: DI-ILD (n=20), FIIP (n=28) and miscellaneous (M-ILD) (n=24). In-hospital mortality rates were 40% (n=8/20), 68% (n=19/28), and 25% (n=6/24) for DI-ILD, FIIP and M-ILD, respectively, (p=0.006). It reached, 64% (n=7/11), 100% (n=17/17) and 60% (n=6/10), respectively, in subjects on mechanical ventilation (p=0.007). In multivariate analysis, the need for mechanical ventilation (OR= 35; [95% CI, 5-255]), the type of ILD (FIIP vs miscellaneous) (OR=22; [95% CI, 3-147]) and high-dose steroids during ICU stay (OR=0.19; [95% CI, 0.04-0.99]) were independent determinants of in-hospital mortality. CONCLUSION: This study, while confirming the poor prognosis of FIIP patients in ICU, highlights the better prognosis of DI-ILD and M-ILD even though severity criteria on admission are similar in these 3 groups. These data impact on the management of these patients in ICU in whom a proper diagnostic of the underlying condition is crucial.